Preventive Action
Many get confused with corrective and preventive
actions. While corrective action deals
with existing nonconformances (defects), preventive actions deal with nonconformities
that haven’t occurred, but might occur in the future.
In section 8.5.3 Preventive Action, ISO 9001 states “The
organization shall determine action to eliminate the causes of potential
nonconformities in order to prevent their occurrence.” Potential problems are usually identified
from the analysis of metrics, or from audits.
For example, an organization has a metric for on time
delivery, and will take corrective action when delivery falls below 95% on
time. The metric is above the limit, but
examination of the metric chart shows that on time delivery has decreased each
month for the past 5 months. A
corrective action is inappropriate because the metric hasn’t fallen below the
requirement (95%). In this case,
preventive action is more appropriate.
Whereas corrective action requires that action be taken,
preventive action does not. Consider a
control chart for a machine tool. The
chart indicates that the tool is wearing and may need to be replaced soon. Do we change the tool now or wait until the
control limit is exceeded? An economic
analysis might suggest that we wait for the control limit to be exceeded because
the cost of the tool is high or the cost of lost production is high. The customer
may be in critical need of the product and we can’t afford to shut down the
machine now. A decision to continue
production would close the preventive action.
A decision to take
action would allow the machine tool to continue operation while a plan is
developed for implementing a replacement.
In contrast, if this were a corrective action, the tool would be shut
down until a replacement is available.
Once the decision to take preventive action has been made,
the process becomes very similar to corrective action. An action is selected, usually by a
team. A plan is developed to implement
the preventive action selected, and the implemented action is monitored for
effectiveness.
Some organizations use one form for both preventive and
corrective actions. In the case of a
preventive action, there is no evidence of nonconformance, and there is no
containment plan, since a nonconformance has not occurred. Root cause analysis still occurs because there
may be many choices of actions to take.
When the action(s) have been identified, a plan for
implementation is developed.
My steps of preventive action look like this:
1.
Problem statement
a.
State the requirement
b.
State the evidence of potential nonconformance
2.
Root cause analysis
3.
Preventive action plan
a.
What action(s) will be taken? NOTE: The plan might be to do nothing.
b.
When will they be implemented?
4.
Follow Up
a.
Were the actions taken effective?
1.
Problem Statement
a.
State the requirement
b.
State the nonconformance
c.
State the objective evidence of the
nonconformance
2.
Containment Plan
a.
When did the problem start?
b.
What are we doing to control the bleeding while
we are looking for a solution ( short term fix)
3.
Root Cause Analysis
4.
Corrective Action Plan
a.
What will be done to eliminate the root
cause(s)?
b.
When will they be implemented?
5.
Follow Up
a.
Was the implemented corrective action effective?
b.
Was the short term fix removed?